For those who often find themselves having to take a call in strange places, France Telecom has invented a phonebooth that works underwater.

Boffins assure vnunet.com that the phone will work at any depth, removing that irrating need for speedy surfacing, leading to a nasty attack of the bends, each time the phone rings on dry land.

The system comprises a buoy fitted with a GSM phone relay that connects to an underwater phone booth. The terminal is connected to the buoy by a wire, and is equipped with a telephone keyboard.

A special mouthpiece prevents the user from drowning while using the phone. The caller has to bite on the mouthpiece and push a button, and sound vibrations are resonated off the diver's skull which acts as a resonance chamber.

The product is pitched at "professionals working underwater", presumably divers, archeologists and victims of rising sea levels.

The phone was first tested by archeologists digging up Queen Cleopatra's palace in the waters off Alexandria. It enabled the divers to ring up for directions during their dig.

While many would have considered the technology of limited use, France Telecom is planning to roll out the system in 2002. The company is investigating a cordless version of the technology that dispenses with the phone box and uses ultrasound or weak electrical currents.